1. Register Today It's free! This box and some ads will disappear once registered!

    Dismiss Notice

Rebuilt 4.6L lacks getup & go

Discussion in 'Stock 2002 - 2005 Explorers' started by JB7795, February 11, 2020.

^^Searches ExplorerForum.com^^



Do Not Sell My Personal Information


  1. JB7795

    JB7795 New Member

    Joined:
    December 10, 2019
    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    1
    City, State:
    Noblesville, IN
    Year, Model & Trim Level:
    2004 Explorer XLT 4.6L
    To make a long story short, I’ve rebuilt this engine and installed a new transmission but truck lacks that throw you back in the seat kind of acceleration. Essentially the truck seems to accelerate okay from a dead stop but once you’re moving at 50-60mph and you give it gas as if you’re about to pass someone or merge onto the interstate, the RPMS shoot up to 4-5K but the truck doesn’t move along with it. You have to feather the throttle in order for it to accelerate at a “reasonable” rate. Truck seems to shift smooth as butter when you feather it, but if you try to get on it, it seems to shift pretty abruptly and harsh...So recently took my 04 Explorer to the ford dealership for a diagnostic, originally was supposed to be $80 but was told it’d cost $400 for them to diag it further so I gave them the go ahead since I’ve already invested so much of myself into this project I wanted a break but I now regret doing so because all they told me after having the truck for two days was that it needed a new battery (already knew that) and that my aftermarket plugs (Bosch) and ignition coils were to blame and I needed motorcraft instead. I thought okay I’ve had experiences with that before on other vehicles where an aftermarket part has caused problems so I buy new Motorcraft coils/plugs and a battery and guess what? Still having the same problems. And to think they wanted to charge me $1,400 to do that LOL 1/2 hour of labor to put a battery in, I’d be concerned if it took a technician half an hour to swap out a battery but I digress. I’m considering going back to this dealership this week and raising hell because I’m not quite sure what I paid $400 for, I mean I would think finding out the battery, coils and plugs were the problem would be a pretty basic $80 diagnostic but anyways just looking for some ideas thanks.
     
  2. Support EF

    Join the Elite Explorers for $20.

    Explorer Forum has probably saved you that much already, and will continue to save you money as you learn how to diagnose fix problems yourself and learn which modifications work without having to experiment on your own. Elite Explorer members see practically no advertisements, can add their own profile photo, upload photo attachments in all forums, and Media Gallery, create more private Conversations, and more. Join Today. Your support is greatly appreciated.



  3. boominXplorer

    boominXplorer Elite Ranger Elite Explorer

    Joined:
    September 16, 2002
    Messages:
    9,094
    Media:
    55
    Albums:
    3
    Likes Received:
    587
    Trophy Points:
    133
    City, State:
    Virginia Beach, Va
    Year, Model & Trim Level:
    00 4x4 Mounty
    Could be weak fuel pressure under load, maf issue or transmission related. Any codes after installing the new battery?
     
  4. JB7795

    JB7795 New Member

    Joined:
    December 10, 2019
    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    1
    City, State:
    Noblesville, IN
    Year, Model & Trim Level:
    2004 Explorer XLT 4.6L
    Fuel pressure is good, checked it before I took it to ford and the diagnostic confirmed the fuel system is operating properly, the only codes it has thrown are misfire codes. Before taking it to ford, the first time I drove it the CEL flashed a couple times then never came back on, put my scanner on it and it had misfire codes stored in the computer then Ford said the same thing just a few misfire codes and low voltage codes from the weak battery. But because of the misfire codes that’s why I believed it could indeed be the coils/plugs but that’s proved not to be the case. Transmission is a reman from a reputable company cost me $2,000, fluid is at the correct level as well. In regards to the engine, I had this truck completely gutted engine down to the bare block, replaced: rod & crankshaft bearings, pistons and rings, head gaskets, valve stem seals, timing set, Motorcraft crank & cam sensors, all gaskets the whole nine yards so needless to say you can already see I’ve spent a lot of money restoring this truck wouldn’t be doing it if it wasn’t in as good of condition as it is. Interior and exterior are damn near mint and I got the truck for only $500 after it sat in a garage for 5-6 years.
    *edit* Wouldn’t the MAF set a code if it were causing issues?
     
  5. JB7795

    JB7795 New Member

    Joined:
    December 10, 2019
    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    1
    City, State:
    Noblesville, IN
    Year, Model & Trim Level:
    2004 Explorer XLT 4.6L
    Not sure about the low voltage codes but the misfire code was just P0300 for random misfire. And this is the 4.6L so it’s got a coil on plug setup, no distributor. Fuel pressure is monitored via a sensor so had to use my scan tool live data to see fuel pressure and the dealership said fuel system is operating properly. Idk if the fuel pump has ever been replaced but I did replace the filter and I can hear the pump engaging when I turn the key on. Also I’ve already replaced the catalytic converter along with everything else. Last night I got a hunch that maybe the MAF sensor was causing issues because after doing some reading apparently it doesn’t always throw a code so I went to autozone and bought a new one which is a reman sensor but I know it’s a Motorcraft sensor because of the “FoMoCo” logo on it. Don’t know if that matters though since it’s been remanufactured, anyways after installation the truck didn’t seem to like that sensor because it immediately ran worse and stalled multiple times throwing codes P0102 and P2106. Is it likely the sensor is no good or am I supposed to do some sort of reset after swapping those sensors?
     
  6. JB7795

    JB7795 New Member

    Joined:
    December 10, 2019
    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    1
    City, State:
    Noblesville, IN
    Year, Model & Trim Level:
    2004 Explorer XLT 4.6L
    Update, still haven’t found the source of the problem but I’m beginning to think it could be something going on with the transmission. When I try and step on it the RPMs shoot up but the truck doesn’t respond. I had the pedal all the way to the floor and the RPMs would not rise above 4K, I tried shifting through it manually as well and the truck acts the same 1st into 2nd gear seems alright but it clunks into 3rd then getting it out of 3rd is rough it won’t shift into drive unless I let my foot off the gas then it shifts but it’s very harsh. I was told by a friend who’s worked with fords for years that it could be something about the “kick down” gear in the tranny, not entirely familiar with what he’s referring to though hopefully someone can shed some light on this
     
  7. TechGuru

    TechGuru Well-Known Member

    Joined:
    August 23, 2015
    Messages:
    1,866
    Likes Received:
    213
    Trophy Points:
    83
    Location:
    Texas
    Year, Model & Trim Level:
    2003 XLS 4X4 4.0L FLEX
  8. JB7795

    JB7795 New Member

    Joined:
    December 10, 2019
    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    1
    City, State:
    Noblesville, IN
    Year, Model & Trim Level:
    2004 Explorer XLT 4.6L
    I’ll have to give this a try and let you know, anything in particular I should expect? I just bought this transmission so I’m really hoping there isn’t anything wrong with it
     

Share This Page







We Support Our Troops!